METAL-ENCLOSED INTERRUPTER SWITCHGEAR PRODUCTION TESTS

Production Tests
Unless otherwise specified, all production tests shall be made by the manufacturer at the factory on the complete MEI switchgear or its component for the purpose of checking the correctness of manufacturing operations and materials. (See ANSI/IEEE C37.20.3-1987.)
Production tests shall include the following:
1) Low-frequency withstand voltage tests
2) Mechanical operation tests
3) Grounding of instrument transformer cases test
4) Electrical operation and wiring tests
Low-Frequency Withstand Voltage Tests
Low-frequency withstand tests shall be made at the factory on each switchgear assembly in the same manner as described in 4.5.2 with the exception that tests across the open gap(s) (see 4.5.1(2)) are not required. Tests shall be made in accordance with 4.5.1(1) and 4.5.2.2.

Drawout interrupter switch removable elements need not be tested in the assembly if they are tested separately. Control devices, potential transformers, and control power transformers, which are connected to the primary circuit, may be disconnected during the test.

Mechanical Operation Tests
Mechanical operation tests shall be performed to ensure the proper functioning of removable element operating mechanisms, shutter, mechanical interlocks, and the like. These tests shall ensure the interchangeability of removable elements designed to be interchangeable.

Grounding of Instrument Transformer Cases Test
The effectiveness of grounding of each instrument transformer case or frame shall be checked with a low-potential source, such as 10 volts or less, using bells, buzzers, or lights. This test is required only when instrument transformers are of metal case design.
Electrical Operation and Wiring Tests
Control Wiring Continuity
The correctness of the control wiring of MEI switchgear shall be verified by (1) actual electrical operation of the component control devices, or (2) individual circuit continuity checks by electrical circuit testers, or by both (1) and (2).
Control Wiring Insulation Test
A 60-Hz test voltage, 1500 volts to ground, shall be applied for 1 minute after all circuit grounds have been disconnected and all circuits wired together with small bare wire to short-circuit coil windings. The duration of the test shall be 1 second if a voltage of 1800 volts is applied. At the option of the manufacturer, switchgear-mounted devices that have been individually tested may be disconnected during this test.

Polarity Verification
Tests or inspections shall be made to ensure that connections between instrument transformers and meters or relays or similar devices are connected with proper polarities. Instruments shall be checked to ensure that pointers move in the proper direction. This does not require tests using primary voltage and current.
Sequence Tests
MEI switchgear involving the sequential operation of devices shall be tested to ensure that the devices in the sequence function properly and in the order intended. This sequence test need not include remote equipment controlled by the MEI switchgear; however, this equipment may be simulated where necessary.

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